I think you mean devolve...
Anyways, Tim defended his title what? Twice? Against Arlovski and Monson, both of which are no longer in the UFC and that includes Sylvia.
Back when the UFC heavyweight division was laughable. GSP is the reigning and 6 time defending welterweight champion. All of his challengers are still in the UFC and considered among the best of the best in the world in their weight classes.
Tim was UFC champ when Pride had the steeper and more talented heavyweight division.
You simply cannot compare the two, to do so is plain ignorance.